diff options
| author | Josh Poimboeuf <jpoimboe@kernel.org> | 2022-06-03 08:04:44 -0700 |
|---|---|---|
| committer | Josh Poimboeuf <jpoimboe@kernel.org> | 2022-06-06 11:50:22 -0700 |
| commit | 7b6c7a877cc616bc7dc9cd39646fe454acbed48b (patch) | |
| tree | fc614303b78a6b3248369ddfa0c1f03c320def88 /tools | |
| parent | dcea997beed694cbd8705100ca1a6eb0d886de69 (diff) | |
| download | linux-7b6c7a877cc616bc7dc9cd39646fe454acbed48b.tar.bz2 | |
x86/ftrace: Remove OBJECT_FILES_NON_STANDARD usage
The file-wide OBJECT_FILES_NON_STANDARD annotation is used with
CONFIG_FRAME_POINTER to tell objtool to skip the entire file when frame
pointers are enabled. However that annotation is now deprecated because
it doesn't work with IBT, where objtool runs on vmlinux.o instead of
individual translation units.
Instead, use more fine-grained function-specific annotations:
- The 'save_mcount_regs' macro does funny things with the frame pointer.
Use STACK_FRAME_NON_STANDARD_FP to tell objtool to ignore the
functions using it.
- The return_to_handler() "function" isn't actually a callable function.
Instead of being called, it's returned to. The real return address
isn't on the stack, so unwinding is already doomed no matter which
unwinder is used. So just remove the STT_FUNC annotation, telling
objtool to ignore it. That also removes the implicit
ANNOTATE_NOENDBR, which now needs to be made explicit.
Fixes the following warning:
vmlinux.o: warning: objtool: __fentry__+0x16: return with modified stack frame
Fixes: ed53a0d97192 ("x86/alternative: Use .ibt_endbr_seal to seal indirect calls")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/b7a7a42fe306aca37826043dac89e113a1acdbac.1654268610.git.jpoimboe@kernel.org
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/include/linux/objtool.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/tools/include/linux/objtool.h b/tools/include/linux/objtool.h index 6491fa8fba6d..15b940ec1eac 100644 --- a/tools/include/linux/objtool.h +++ b/tools/include/linux/objtool.h @@ -143,6 +143,12 @@ struct unwind_hint { .popsection .endm +.macro STACK_FRAME_NON_STANDARD_FP func:req +#ifdef CONFIG_FRAME_POINTER + STACK_FRAME_NON_STANDARD \func +#endif +.endm + .macro ANNOTATE_NOENDBR .Lhere_\@: .pushsection .discard.noendbr |